Ball safety net.  There is a tennis court behind the field, and when the soccer players shoot on the goal, the balls flies into the court.  If someone is using the court, the potential to get hit by a flying ball is there.  If no one is using the court, players must still go into the court to fetch the balls.  If a net was placed behind the goal post, it could stop the balls from going into the court.  This could also help the football team during field goal practice.  In addition, a net could also be placed behind the opposite goal.  This would prevent balls from going onto the road and potentially onto the highway.

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